CrossWordFalcon : free and open-source crossword generator and player

[Etienne]

Hi !

For few weeks I'm working on a new software.

Demo server here:
https://falcon.cubaix.com/

Few crossword samples here:
https://github.com/EtienneAb3d/CrossWordFalcon/blob/main/GRID_SAMPLES/README.md

Fully human work to fully automatic crossword and clues generation, with many tools using AI to help in interactive mode.
Currently six languages (including bilingual grids).

Please feel free to share your comments to help me improve it!

Etienne

[Etienne]

Features

Crossword generation

• Six languages: French, English, German, Spanish, Italian, Portuguese.
• Bilingual grids: across words in one language, down words in another.
• Any size from 5×5 to 50×50, plus ready-made formats ("Préconfigurations"): grids up to 30×30 work reliably; 50×50 is still being fine-tuned.
• Three difficulty levels (Easy, Medium, Hard).
• Symmetric black-cell layouts: horizontal, vertical, diagonal, both ways, or rotation.
• Seven levels of computing effort for filling the grid automatically, from the quick "Flash" to the exhaustive "GridZilla".
• Themed grids: vocabulary and clues steered toward a subject you choose.
• "Challenge Words": force your own words into the grid.

Clues

• Clues written automatically by an AI language model, in the grid's language.
• Grounded in real dictionary definitions, grammar and example sentences.
• Short generated title for every grid.
• "Recompute": rewrite every clue of a grid, saved as a new version.
• Local AI model by default; optional cloud AI models (Mistral, Claude...) with automatic fallback to the local AI model.

Playing

• Playable grid in the browser, with keyboard or on-screen keyboard.
• "Check" and "Solution" buttons, without losing your answers.
• Zoom and sliders for large grids.
• Grid statistics: word count per length.
• Timer and progress saved under your nickname; resume anytime.
• Per-grid leaderboard (correct letters, then time).
• Shareable "Play" link for each grid.

Interactive mode (build a grid yourself)

• Place words one at a time ("Next") or by hand, undo step by step.
• Toggle black cells by hand, mirrored if the symmetry option is on.
• Word suggestions per slot, per crossing, by start or end.
• Warnings on letters that would block a crossing word.
• Highlighting of impossible, poor and set-aside slots.
• Letter statistics for every empty cell.
• "Clean": remove impossible zones automatically.
• "Finish the grid" / "Finish the zone": let the generator complete it.
• Suggested and automatic definitions, suggested titles.
• "Correct": fix spelling and grammar in a definition or title.
• Drafts saved automatically ("Créations"), publish to the Library.
• Reopen any Library grid, or any generation attempt, for editing.

Library and export

• Every grid stored in a shared Library, filterable by language and level.
• Player count per grid; "seen" tracking.
• PDF download (one or two A4 pages).
• Across Lite .puz download.
• SVG/PNG images of each published grid and its solution.

Tools

• Dictionary: same-root search, real definitions, AI-proposed definitions.
• Synonyms and theme-related words.
• Paraphraser: 5 rewordings of a sentence.
• Bilingual lookups side by side.
• One-click links to Perplexity, ChatGPT, Claude, Mistral and Euria.
• David FALCON: chat assistant for help and hints, without spoiling answers.
• Crossword news panel (RSS feeds and publishers' daily grids).

Interface and deployment

• Interface in six languages, following the chosen language.
• Nickname protected by a secret word.
• Online-user counter and CPU/GPU load meters.
• Runs entirely locally, on CPU or GPU (NVIDIA, Apple Silicon).
• Optional dual-GPU setup.
• Server available in Python or Java, interchangeable.
• Batch generator to pre-fill the Library.
• Command-line generator.
• Dictionaries rebuildable from their original sources.

[Etienne]

Now clearly offers 2 crossword pattern styles to build crosswords (for both fully human work to fully automatic grid/words/clues generation):

• sparse-French pattern style
• grouped/aligned-American/NYT pattern style. Improved/optimized.

Please feel free to share your comments to help me improve it!

[Etienne]

You now have precise control over a mix of three styles for generating random black-square patterns: % sparse (French), % grouped (American), % aligned (American).

[admin]

Hello Etienne,

Excellent. It would seem you've put much work into this project. Python. Thank you.

I have technical questions. (server-side/PC ?, OS (Linux, Windows). Implementation. I want to get my head around it. I'll be in touch.

Thanks for your efforts and sharing.

-Kevin

[Etienne]

Hi Kevin,

Thank you for your attention!

On the principle, since all parts are cross-platform, it should be installable on all kind of OS: Windows, Linux, Mac (Intel/Silicon), etc. Of course, not all tested on my side, thus certainly some tuning are to be done to succeed with all parts of the code.

My own demo server is Linux (a few technical informations are available on the help hint on top-right of the interface).
The Front/Middleware side is Python. The Back side may be Python or Java (currently Java, much more efficient for the crossword builder algo).
The semantic part (similarity search, thematic glossary creation) is a Qdrant vector database using its ready to use Docker, and a small Qwen3 0.6B embedder (CPU via LlamaCpp).

For the data preprocessing (no need to re-evaluate for a new installation): word statistics were done on a large opus.nlpl.eu corpus set, word/multi-word were enriched with Scrabble dictionaries, Hunspell (also used for its grammatical typologies), and Wiktionary (also used for its definitions). Usage scoring of words and multi-words was done using a local small Qwen3.5 9B LLM (2x3060 12G GPUs using vLLM).

Clue helper is using Mistral Small.
The ChatBot is also using the local LLM.

I would really enjoy all kind of feedback/exchanges!